docs: def split(self):
          """
          Split an ambivalent location into 2. One for the x, the other for the y.
          ::
  
              >>> l = Location(pop=(-5,5))
              >>> l.split()
              (<Location pop:-5 >, <Location pop:5 >)
          """
          x = self.__class__()
          y = self.__class__()
          for dim, val in self.items():
              if isinstance(val, tuple):
                  x[dim] = val[0]
                  y[dim] = val[1]
              else:
                  x[dim] = val
                  y[dim] = val
          return x, y